Software applications, such as accounting, finance, and customer relations applications, may constitute a large, ongoing investment by an enterprise or other organization. For example, an enterprise information technology (“EIT”) organization may invest in the initial requirements gathering and design of an application. Then EIT may invest in the software programming, development and testing of the application. Next enterprise data will have to be entered or ported into the application. Finally the application will be deployed, often constituting an expense of both hardware and/or training.
As the application is used and modified during its lifecycle, the application accrues modifications and bug fixes, as well as an accretion of business unit information technology (“BUIT”) satellite applications. In this way, an ecosystem builds around the original software application. Eventually the application may become relied upon by the enterprise as the embodiment of the enterprise's policies. Thus, a software application not only represents a financial investment, but also an institutionalization of the enterprise's business procedures.
However, technology platforms evolve and business needs and policies evolve. An example of the former is where an initial investment in a two tier client server software architecture may give way to three tier enterprise data center based architectures which in turn evolve into web based applications and cloud based applications, each time causing applications to be ported to the newer software architectures. Another example of the former is where programming languages and frameworks become deprecated, such as where Microsoft Visual Basic.NET™ and the .NET application framework was not fully backwards compatible with Microsoft Visual Basic 6 and its Component Object Model based infrastructure, giving rise to applications being ported. An example of the latter is where the C Standard Library <string.h> library was later found to be susceptible to buffer overrun security attacks, causing applications to be moved to fixed buffer equivalents.
Typically, porting an application to a new software architecture, or platform causes a full rewrite. Since the rewrite is to a new architecture, or platform, or represents some other form of code refactoring, the port will not behave exactly in the same way as before. For example, a personal computer based client application may be ported to a mobile device. Accordingly, the functionality of the ported application on mobile device will differ at least according to the form factor change.
The functionality change causes risk that the semantics of the rewrite will not exactly conform to the behavior of the original application. If this were to happen, BUTT satellite applications and other software applications interfacing with the original application may break.
This state of affairs leaves EIT organizations on the horns of a dilemma. The extension of the lifecycle of their mission critical software applications may rely on a successful port to a new architecture or platform. But to do so, the EIT organization may have to risk a non-conforming port. In other words, the EIT organization cannot rely on semantics to be preserved during a port.